Joint working of flames and arcs and apparatus therefor



June 1 1926.

(5. T. SQUTHGATE JOINT WORKING OF FLAMES AND ARCS AND APPARATUS THEREFORFiled Mayz'7- 1924 June 1 192% 1,587,197

e. T. SOUTHGATE JOINT WORKING OF FLAMES AND ARCS AND APPARATUS THEREFORFiled May '7, 1924 3 Sheets-Sheet 2 June 1 1926.

1 587 19? T. souTHGATg JOINT WORKING OF FLAMES AND ARCS AND APPARATUSTHEREFOR Filed May 7, 1924 g f I a I l l I i u i s Q I i 9 L.

| 1 l 0 ODQZA a FE 54 i w g u i Q 1 z I i 5 r if i 4; u

48a 45a 20 47 7 I l6 55 i 1 $31 56 1% J:

Invenmn liatented June 1, 7 1926.

warren STATES GEORGE THOMPSON SOUTHGATE, OF ANNISTON, ALABAMA.

some woanrns or names AND anus AND srrnna'rus mnnnron.

Application filed May F,

The invention relates to the joint use of combustion flames and electricenergy in thermal, thermo-chemical and electrochemical effects andparticularly to an improved process and apparatus for producingcombustion flames having electric arcs extending along the same.

It has already been proposed to arrange a pair of electrodes with their"arcing tips disposed in front of a flame projecting nozzle, the arcingtips being spaced trans versely of the flame stream and'the are beingelongated into U-shape by the blast, and it has been proposed to usecombined electrode and nozzle structures for the formation of arcs alongthe flame stream, the arrangements being such that the arcs spring fromthe nozzle or from a point so near the nozzle that the arc could strikeback thereto.

The present invention relates to the for mation of arcs extending along,as distinguished from across, flamestreams,,the apparatus and processbeing such that the arcs are spaced from the nozzle structure and cannotstrike back thereto. The apparatus is characterized by the rovisioni offlame-projecting nozzles and rigid electrodeshaving their arcing endsspaced from the nozzles. The electrode tips are positioned in or closelyadjacent to the combustion flames, and the electrodes may extend throughthe nozzles or they may lie outside the same and pass obliquely into orto points adjacent the combustion .flames. In working with suchapparatus under my novel process, the [supplied fuel and air areprojected from the nozzles at such velocity 'that the arcs cannot strikeback to the nozzles. A

The invention permits the use of relatively large bodies of combustionflame with much smaller proportions of heat from electric energy. Thecombustion flames may be reducing, neutral or oxidizing, and the currentsource may be either direct or alternating, but is usually of relativelyhigh voltage. In the accompanying drawings Fig. 1 is alongitudinal'midsection and Fig. 2 is a cross section in the plane 2-2of: a typical nozzle-electrode constituting one form of my improvedapparatus;

Fig. 3 illustrates a preferred manner of 1924. Serial No. 711,615.

leading water to and from the nozzle or any other part of the apparatuswhich it may be desired to cool with water;

Fig. 4 IS a lan of three of the improved nozzle-electr es in one of thehrrangements sultable for three-phase operation in a closed chamber;

Fig. 5 is a plan of two nozzle-electrodes su tably arranged foroperation from different types of electricity supply and showingv theconnections made to the nozzle-electrodes and to the objective-uponwhich the fuel electric flames impin e;

F gs. 6, 7 and 8 show t e invention embodied in a furnace for smeltin ormelting operations; Fig. 6' being part y an elevation and partly avertical midsection, Fig. 7 a vertical section in the lane 7-7, and Egg8 a plan section in the irregular planes to the outlet end of the nozzlefor a mix ture thereat, but a simpler arrangement is obtained byintroducin the fuel and air together at the rear en of the nozzle bore14c. A if-inlet 14 cooperates with the bore 14 to form a blowpipe Whichis supplied with fuel through the pipe 15 and fuel valve 16, which partsare separated from i the blowpipe inlet by a hollow electric insulator17 The pipe 15 is fed from a main 18 which may be the usual pressureheader when a liquid or gaseous fuel is used. With powdered fuel, themain 18 should be provided with means, such as a revolving screw, forinsuring a ready feed into the inlet 14*. The air or other oxidizing gasis led to the blowpipe by way of pipe 19, valve 20 and electricinsulator 21, the supply being from pressure main 22. An electricterminal 23 and lead wire 24; connect the nozzle to a suitable source ofelectromotive force. i

Within the bore 14 of each nozzle 11 is ice res

arranged an electrode 525 may Q i I 145 3749? a fluid-eboledmetal'Qtubehaving a renewable arcing'tipQ By providing thesolidrods or packed tubeswiththreaded ends 2.6, new

forward fandcom'- letely consumed. To insure good electr cal contactbetween the electrode "and the nozzle as well as to preventinadvertent-movement of the electrode, the

nozzleis provided with-fa slip tube 27; of

such dimension'sasto fit the electrode rather snugly. when the a paratusis used in a furnace workingun er a pressure higher than atmospheric,the outer end of theslip tube is provided withj-a paclfing gland 28. Theslip-tube is preferably extendedzbeyond' the-nozzle 11b arefractoryportionfl29 which" protects t e electrode against; exces siveoxidation b flame 12. i

.''-For the supp y"; f?

whereby water=isdelivered th ;.to' andfrom the nozzle in, broken nectionthe .water supply system and' the and between" the nozzle and thenozzle-electro es.

hjch the noz'z e 33 capable of,

ate the The sprayed water falls into funnel -35wand i is carriedgtonozzlell bypipe" 3& From nozzle 11 the spent 'waterissimilarly'discharged to the drainage system'via pipe 37,-nozzle 3-8,spray 39, funnel 40,-pipe'41f. and-drain header 42.

In furnace structures, each of the nozzles is electricallyinsulatedfrom, the structure and Supported by aninsula'tor43 ofthermally refractory material which maybe buil't'directly into themasonry of the furnace. -The' bores of the insulators are fluted withalternating channels 44 and ridges 44, which ridges bear a ainst andfirmly support the The i-nsulatorsprefcrably extend within the-furnace'to the ends rotect the latter from by radiation from the furnaceinterior, w 'ich' extended length also insures superior electricalinsulation by. providing agreater length of electrical creepage sur-"face.

The outer ends of the nozzle-electrode assembly are enclosed by a windbox 45 which .is supplied, by air pipe 45*, with air from a suitablesource, such as a centrifugal fan or arotary blower. From wind box 45,air

- passes to the. furnace through the channels 44 as a'supply ofsecondary air for insuring .through the nozzle with the primary air afor the burning of unoxidized gases 'evol'eii within the furnace. Thissecondary jiftai" p supply cools the nozzles and the wind box sectionsmay be attached at the outer ends of theelectrodes, the stumps be ngpushed 45'insures the safety of the operators by "enclosing theelectrically live parts. A su1t-.

able sight window 46 is provided, preferabl inthe hinged cover 47 ofthe-box. Door 4 preferably operates a contact 48 in circuit with a relayupon the main switch, the

that the electric parts within the wind box are pot alive when -therelay circuit isbroken. When the door 47 is open the relay operator{ andto the apparatus, the wind cooling .wate'rtofthe box 45,?air duct45f=and conduit 48 should gaseous or powdered fuel is used." The-s'trictured orifice 49 is preferably -formed by -'mounting a bushing 50over the slip tube 27 fits junction with the refractory extension 1.29,which bushing may act as the coupling ;u .the-disch'argedwater into asprayifi of Small-drops; Valve 32 is i pipe 31* and used to resupply-1'- ofwater discharged in t e spray.

between the slip-tube and the extension. The bushing-'50 is centered inthe nozzle '11 by narrow, low ridges 51. Liquid fuel, for

. -power and relay circuits being so arranged example oil, enters theY-i-nlet 14 from fuel pipe 15 and is entrained in and mixed with theprimary air as it flows through the nozzle bore -14, being atomized orfinely sprayed therefrom and into the combustion flame as it passesthrough the strictured orifice 49. Figs, 6, 7 and 8 show-a furnacecomprising a stack 52 and hearth 53, which furnace is one "of theseveral types in which the invention-may be employed. Stock 54 isfeddown the shaft, preheated and melted therein, and further melted in thehearth where i the 'final physical and chemical transforma tions takeplace. 'The hearth is provided with'a'tap hole 55 and with a peep-hole56. By providing ample space for the combustion' offuelthe dimensionsare suitable for the projection of relatively long arcs 57 andcommercial line voltages may be employed.

.In practical operations I have employed electromotive' forces rangingfrom (300 to 6000 volts and both alternating and direct currents havebeen successfully used.

As shown in'Figs. 4 and 6, the electric arcs need not reach the furnacestock but may mutually join, each other and play in the space abovetherbat h. With threephase alternating current anassembly of threenozzle-electrodes is used, .each'leg of the supply circuit beingconnected to an individual nozzle. While no neutral connection isreuired, if one is available it may be made to t e bath in the usualmanner.

The supply connections shown in Figxb are alternative, that is, any oneof the six illustrated supplies may be used. The systern of supply showndiagrammatically at the top of the diagram is a three-phase supply 58,delta-connected with the t ird point of the delta connected to thecrotch or impingement point of the arcs, which connection may beeffected through the stock or work 59 upon which the flame-arc is Irojected, The supply 60 is a quarter-puse alternating current with aneutral connection. The supplies $1 and 62 are three and systems, andthe supplies 63 and M areglre two wire, respectively, direct currentsupply spectively, three and two wire, single-p ase alternating currentsystems. The are may be formed in space or the crotch oil the are mayimpinge upon an objective, such as the charge in the stack 52, which obect1ve may be connected to the neutral 0:? a threewire direct oralternating current circuit.

To put the apparatus in o oration the electrode tips are arranged welbeyond the ends of the nozzles and fuel and air are ad- Kill mitted tothe nozzle bores, the combustion flame being i ited by any suitablemeans and the supp y valves ad usted to give a fairly still blast flameburning around and beyond the electrode tips. Upon closing the mainswitch electric arcs will play from the end of each electrode in andalong the respective combustion flame to their junction or to the commonobjective upon which they impinge. The velocity at which the fuelmixture is projected should be such that the arcs'cannot strike backalong the flames and into contact with permanent parts of the innstallation.

in operating my improved process in a hearth furnace ll discovered thatthere is a great acceleration of the fuel combustion itself because ctthe'pronounc'ed ignition effeet of the intense electric arcs. Thediscovery was made when it was observed that the and air supply,signifies more rapid and consefluently hotter combustion. That this wasin eed the case was clearly indicated by the greater brilliance of. thecombustion tlanies "even much beyond the lengths of the area.

The are operation is satisfactory whether the combustion flame bereducing, neutral,

or oxidizing, but with an oxidizing flame electrodes of metal tubespacked with carbonaceous matter are superior to naked carbon or graphiterods as they resist oxidation better. As the electrodes burn back by areconsumption the regulationot current magnitude is obtained by advancingthe rods either by hand or by suitable electromag netic mechanism. I

It is usually preferable to supply the greater part of the energy byfuel and to use only such smaller portion of electrical energy as isrequired to give the desired increase of the joint temperature by the onceedingly high temperature of the arc. The invention permits the useofany ratio of electric to liuel energy and with perfectly stableoperation. With furnaces containing relatively large burdens such thatconsiderable storage of high-intensity heat is practicable, electricitymay be used only intermittently during periods of the day whenelectricity may be purchasedcheaply, yet it may be used effectively inmaintaining high average temperature and productivity by intermittentincrements of intense super heating. i

The process may be used in connection with the gas, oil or powdered fuelburners commonly employed under steam boilers, resulting in big ortemperaturesand particularly in more stable operation when lowgrade orrefractory tuel is employed. in this and otherv applications of theinvention the electrodes need not extend through the nozzles but maypass obliquely into the corn bustion flame somewhat beyond the end ofthe nozzle. With a single fuel nozzle and flame, two electrodes are usedwith their arcing portions in contact with the flame, one nearer to andthe other farther from the nozzle.

Substances to be subjected to the'intense heat of the flame arcs may beintroduced throue'hthe nozzles in gaseous, liquid or granulated form, orthey may be agglomer ated into the electrodes. lll hen high voltagedirect currents are employed, advantage may be taken of electrolyticeffects in the arcs. The introduction into the flame of the vapors ofcertain substances increases the electric conductivity and improves thesteady arcing action oil the flames. Granular substances containingmoisture or gases in unstable ccndition are disrupted into much finercondition when introduced into the flames. For

example, iinely powdered quiclrlime is ob I teined when granularlimestone is passed 1 1 through the nozzle and into the combustionflame.

l t is obvious that thesteps of the proc void 4 as well as thearrengement of the apparatus -may be varied without departing {from thespirit of my invention,

The nozzles may be formed or": refractory material other than metal andordinarily fluid cooling of the nozzle is not necessary 7 wt... a liquidfuel is employed. The sup-1 porting blocks 43,-niaybe of metal, suitableinsulation being providedwhen. both; the blocks and nozzles aremetallic. 1A single block maybe provided with a plurality ofcl'iannelsfor receiving the plurality of noz- 'zles of a singleassembly.

In place of forming the are within and" along the flame it may bedirected along and close to the. flame by a blastof air or other ga-s.On the other hand, a particularly thorough intimacy between thecombustion flames and the electrodes may be obtained a ,by the use of abundle of small rods in place 99 or more of the nozzle'elec'trodes of anassem- 1blymay be pivotally supported for varying i the angle ofconvergence between the electrodes. These and many other modifica-",ftions fall within the scope of the" invention.

f Vhile the invention has-beenshown f'rlescribed as embodied in afurnace struc :ture, it will'beapparent that the novel procamaapparatus-may be employedin'the an ting, welding or other local heatingof 9 metals-or other solids.

; I claim: 4 1. In heating'by a combustion flame and an electric arcsuperposed on and extending longitudinally of the flame, the processwhichconsistsin establishing -the'-stream of prises establishing astream of flame and an and-in'directing the arcjto and along the fflamestream by a gaseous blast- Which is passed over the arcin g'- .portionofthe elec-- .14 a v 2. In the process ofjheating by a combusjtion flameand a superposed arc originating atv a source spaced .from the source ofa.

trode.

stream. of flame, the step which comprises directing the are to and.along the-flame .stream by a blast passing over the arc s ourceatsuchveloc'itythat the arc cannot strike" back to the blast-producingnozzle. a

3.'In heating by the joint working of combustion flames and electricares, theprocess which consists. in projectinga blast of oxidizing-gasmixed with fuel from a nozzle and lgnlting the same 'to 'establlsh-astream of flame, forming an are between portions of rigid electrodesspaced from said nozzle and at different points along the stream offlame, and maintaining the velooityof the fuel mix: ture such that thearc cannot strike back to the nozzle' 4. The process of heating mobilesub-- stances at'high temperatures which comare from independentsources, directing said are upon and along said stream offlame by agaseous .blast, andblowing into 'said flame stream the. mobilesubstances to be .heated. 5. The process of electrolytically treatmgmobile substances at high teniperatures,

flame, uperposing upon said stream of flame a direct current areestablished'between' elecftrodes having their arcing portions located atdifferent points along the flame stream and spaced from the sourcetherepf, and 1ntroducing said mobile substances into said flame streamby a" gaseous blast.

prises incorporating said substances in electrodes, establishing astream of flame, draw- ;ing auarc from an electrode which includestlie'substance to ,be heated, and directing a gaseous blast.

7. .The invention as claimed in claim 6,

- which" comprises: establishing a ,stream of.

eoi

saidarc to and along said stream of flame by wherein the electricsupplytosaid are is "direct current, whereby'the substances-may be subjectedto electrolytic treatment.

1- 8.1a apparatus forheating by the joint use of an electric arcand "acombustion the arcing portion. ofsaid electrode and alongthe. stream offlame, and means for the arc cannoti strike back to said nozzle.

' 9. Apparatusfor heating by superposing an-el'ectricarc upon and alongacombustion flame and the are. from independent sources,

' tionbeingso spaced from the nozzle that the gaseous blastif'preventsthe. are from striking back to the nozzle. 4

combination with a nozzle for projecting a stream "of-flame,ofa{'plurality of electrodes having the arcing portions thereof spacedl1.- In apparatus for. combustive and electric'he'ating, anozzle-electrode comprising a nozzle having a bore therethroughforprojecting .fuel and oxidizing matter into a stream of flame, and anelectrode coaxial with said bore and having an flame, means forsuperposing an arc and alonga stream of flame comprising an electrode, anozzle for directing a blast overt 10. In apparatus gfor' heatinglfby'super- .posing an electric; fupon-af fla'me the 6 fromsa'id nozzle and.at"difl'erent, distances "therefrom.,

arcing portion projecting beyond said nozzle.

.:- '12. In apparatusfor c'bmbined combus tive and electric heating, anozzle-electrode comprising a nozzlehaving abore .there through, a tubewithin said bore, a-rigid electrode slidable through said tube andhaving an arcing portion projecting beyond said nozzle,-anda refractorysleeve project- "ing beyond said tube for protecting the'electrode fromoxidation,

' 13. In apparatus for combined combustive and electric heating, thecombination with a plurality of nozzles arranged with their boresdirected toward the space to be heated, of meansfor projectincombustible matter and an oxidizing was rom said bores, andrigidelectrodes having arcing portions spaced from said nozzles. p

14.- Apparatus according to claim 13, wherein the nozzles are sodirected that their flames meet each other in space, whereby their arcsalso are made to meet each other-in space. 1 r V 15. Apparatus accordingto claim 13, combined with means for sup lying secondary air around thenozzles an into the combustion space.

16. Heating apparatus comprising a .noz-

zle for progecting a fuel mlxtu're into a. ame, a thermally refractorystream of bushing surrounding said nozzle and having its walls spacedtherefrom to permit the introduction of secondary air, and meanscomprising a rigid. electrode having an arcing portion spaced from saidnozzle for superposing an are upon and along the flame stream.

'17. In a furnace, the combination of a plurality of thermallyrefractory bushings their bores substantially integral electrodesprojecting beyond .the ends of said nozzles,

of means for roducing combustion flames from said nozz es andsurrounding said electrodes, and means for supplying electricity ofsuitable electromotiy'e force to said electrodes to cause electric arcconduction in said flames.

In testimony whereof I afiix my signature.

GEORGE YT. SOUTHGATE.

